I just ordered this small unit as a couple of people on Amazon said they did something similar to a 12 volt fan. I also did some reading and see where some have cleaned an old dirty fan to make it quieter. I think I will remove the unit and clean it up. Also I'll line the exhaust chamber with some insulation tape and remount the fan assembly with some rubber grommets. I really don't see any other option. I'll take some pics of the job.
https://www.amazon.com/gp/product/B075FN4H37/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1